Optical cross-coupling mitigation system for multi-wavelength beam combining systems
View Patent ↗A system and method for increasing efficiency and power output of a multi-wavelength beam combining system through providing a common output coupler to reflect feedback that stabilizes or individually seeds each emitter, and wherein the individual feedback is preserved by mitigating cross-coupling, wherein a multi-wavelength beam comprised of radiation having a plurality of wavelengths, high brightness and power.
1. A wavelength beam combining laser system comprising:
a plurality of beam emitters each emitting a beam;
a dispersive element for receiving and dispersing the beams;
a cross-coupling mitigation system for receiving and transmitting the dispersed beams while reducing cross-coupling thereof; and
a partially reflecting output coupler positioned to receive the beams transmitted by the cross-coupling mitigation system, transmit a first portion thereof as a multi-wavelength output beam, and reflect a second portion thereof back toward the cross-coupling mitigation system,
wherein the partially reflecting output coupler is disposed within a Rayleigh range of the beams transmitted by the cross-coupling mitigation system.
2. The system of claim 1 , wherein the cross-coupling mitigation system is afocal.
3. The system of claim 1 , wherein the cross-coupling mitigation system comprises an afocal telescope.
4. The system of claim 1 , wherein the cross-coupling mitigation system comprises a first optical element having a first focal length and a second optical element having a second focal length, the first optical element being disposed optically upstream of the second optical element.
5. The system of claim 4 , wherein the first focal length is at least two times greater than the second focal length.
6. The system of claim 4 , wherein the first focal length is at least seven times greater than the second focal length.
7. The system of claim 4 , wherein each of the first and second optical elements comprises a lens.
8. The system of claim 4 , wherein the first optical element is disposed within a Rayleigh range of the dispersed beams from the dispersive element.
9. The system of claim 4 , wherein the partially reflecting output coupler is disposed within a Rayleigh range of the beams transmitted by the second optical element.
10. The system of claim 4 , wherein an optical distance between the first and second optical elements is approximately equal to a sum of the first and second focal lengths.
11. The system of claim 1 , further comprising focusing optics for receiving the beams emitted by the beam emitters and focusing the beams toward the dispersive element.
12. The system of claim 11 , wherein an optical distance between the plurality of beam emitters and the focusing optics is approximately equal to a focal length of the focusing optics.
13. The system of claim 11 , wherein an optical distance between the plurality of beam emitters and the focusing optics is greater than a focal length of the focusing optics.
14. The system of claim 1 , wherein the dispersive element comprises a diffraction grating.